Alexander Markovich Konstantinopolsky (Russian: Александр Маркович Константинопольский; 19 February 1910 – 21 September 1990) was a Soviet chess player, trainer and writer.

He was a five-time champion of Kiev, and trained the world title challenger David Bronstein from a young age.

His prize pupil was the young David Bronstein, who eventually challenged for the World Championship title in 1951, drawing the match against Mikhail Botvinnik.

He was one of the Ukrainian pioneers who developed the King's Indian Defence into prominence, along with Boleslavsky and Bronstein.

During this time, he played one of the earliest games in the Yugoslav Attack against the Dragon Variation of the Sicilian Defence, a line which would become very popular about 20 years later.

He also defended the Dutch Defence with success at a time when it was rarely played by top players.

Konstantinopolsky had a very wide opening repertoire with both colours, a very valuable attribute which he passed on to his prize pupil Bronstein.

He played in the tournament Leningrad / Moscow 1939, scoring an excellent 8½/17 against an exceptionally strong field.

He played in the 1945 Moscow City Championship, probably on average the strongest such event in the world, scoring 9/16.

His over-the-board play seems to have largely stopped about 1955, as he concentrated more on correspondence chess and on his job as a trainer and coach.

So, his best results in the Soviet national championships, which during that period were the strongest tournaments in the world, were four times in the top six (1937, 1945, 1948, 1950).

His best games show he could hold his own with anyone in the USSR, with victories over Botvinnik, Keres, Kotov, Boleslavsky, Grigory Levenfish, Vasily Smyslov, Salo Flohr, Alexander Tolush, Viacheslav Ragozin, Andor Lilienthal, Viktor Korchnoi, Yuri Averbakh, Ratmir Kholmov, Boris Verlinsky, and others.

According to his game files, he only had one chance to play over-the-board in an international tournament outside the Soviet Union, the 'B' section of Amsterdam 1966, when he was well past his prime at age 56.

An exchange sacrifice sets up a very deep trap winning White's Queen; this line was eventually jointly named for Konstantinopolsky's pupil Bronstein.